As known, it is now common in bicycles to use disc brakes. Such brakes are indeed often preferred to conventional brakes of other kinds since they ensure a high braking force and are less subject to problems caused by mud or water.
Typically, a disc brake comprises a caliper fixed on the frame of the bicycle and a brake disc mounted on the hub of the wheel. Inside the caliper there are two or four opposite pads. The brake disc rotates inside the space defined between the opposite pads. By actuating the brake lever, the pads are brought towards the brake disc, generating friction on the brake disc and, consequently, braking the wheel.
The mounting operations of the wheel on the frame of the bicycle (both the first mounting operations and the wheel change/replacement operations) thus provide for the positioning of the brake disc associated with the hub of the wheel inside the space defined between the opposite pads of the caliper and the locking of the ends of the hub on the frame of the bicycle.
The Applicant has observed that in the mounting operations of the wheel it is desirable to obtain the precise centering of the brake disc between the pads. In this way, indeed, following the actuation of the brake, both pads work and in an identical manner, maximizing the braking action and minimizing the differences in wear between the opposite pads. Moreover, the risk of the brake disc touching one of the pads when the brake is not actuated is avoided. This would result in an undesired reduction in speed of the bicycle, for the same effort of the cyclist.
What has been outlined above is of particular importance in the racing bicycles.
The Applicant has noted that, particularly in the case of replacement of the wheel (for example due to a puncture), there is the real risk of not obtaining the desired centering of the brake disc between the pads.
According to the Applicant, this is due to the dimensional and mounting tolerances of the various components of the hub. Therefore, the position of the brake disc along the longitudinal axis of the hub may not be identical in different wheels, so that the mounting of different wheels on the same frame can lead to a different positioning of the brake disc between the pads.
The Applicant has observed that the problems linked to the incorrect positioning of the brake disc between the pads are accentuated by the fact that the pads are very close to one another. Therefore, even a small difference in axial positioning of the brake disc on the hub of the various wheels results in a large difference in axial positioning of the brake disc with respect to the pads.
The Applicant has also observed that the aforementioned problems are even more accentuated in the case of mounting/changing a wheel during a race or, in general, in all those cases in which it is necessary or desired to carry out the wheel mounting/change in the shortest possible time. In these cases, indeed, it is not possible to dedicate time to possible adjustments or modifications of positioning of the various components of the hub and/or of the braking system.
The Applicant has found a solution that makes it possible to ensure the precise centering of the brake disc associated with a bicycle wheel between the pads of a caliper associated with the frame of the bicycle, even in the cases of wheel change.
The Applicant has observed that a requirement similar to the one discussed above with reference to the brake disc occurs in the rear wheel of the bicycle with reference to the sprocket assembly mounted on the free-wheel body. Indeed, it is desirable to obtain the precise positioning of the sprocket assembly with respect to the frame of the bicycle to allow the correct engagement of the chain with the single sprockets of the sprocket assembly.
The Applicant has realized that the precise positioning of the sprocket assembly is as well achievable using a calibrated washer in the hub of the rear wheel of the bicycle.
The Applicant has observed that both the hub for a front or rear wheel with disc brake and the hub with free-wheel body for a rear wheel comprise a pin extending along a longitudinal axis, a cap associated with a free end portion of the pin and configured to be associated with the frame of the bicycle and a body rotatably mounted on the pin through at least one bearing and configured to support the disc brake or the sprocket assembly.
The Applicant has realized that the precise positioning of the brake disc and of the sprocket assembly with respect to the frame can be obtained by adjusting the axial position of the body of the hub that supports the brake disc and of the free-wheel body, respectively, and that such adjustment can in both cases be obtained by using a suitable calibrated washer in the hub of the bicycle wheel.